This invention relates to the reaction products of the alpha-halogenated half esters or amides of succinic acid and thiadiazole dimercaptides as new compositions of matter and their use as lubricant additives possessing multifunctional properties such as extreme pressure, antiwear, antioxidant and anticorrosion.
Compounds of the present invention have several useful properties as lubricant additives. Most of the literature on oil additives discloses novel compositions which possess one useful property for each invention. For example, U.S. Pat. No. 2,836,564 discloses the condensation products of alpha-halogenated aliphatic monocarboxylic acids and 2,5-dimercapto-1,3,4-thiadiazole as new compositions of matter which possess only one useful property, namely corrosion and/or rust inhibition. In addition, there is nothing in the literature that discloses or suggests the use of the above new compositions as multifunctional lubricant additives.
One of the useful properties according to the present invention is the inhibition of corrosion or rusting of metallic surfaces of equipment employing lubricants, especially in equipment where steam or water is present. As little as a 0.03% concentration in a lubricating media inhibits rusting of metal surface which is in contact with sea water at 60.degree. C. for more than two days. Another useful property imparted to lubricants according to the present invention is reducing wear and friction to metal surfaces of machinery operating under heavy loads, where metal slides against metal, resulting in deterioration of conventional lubricants and excessive wear. The novel additives of the present invention also impart extreme pressure (EP) and antioxidant properties to lubricants.
Typical performance data for the products of the invention, including EP, antiwear, and rust inhibition properties are recorded in Table I.
The invention also relates to a number of novel intermediate compounds useful in preparing the thiadiazole lubricant additive compounds of the invention.